Restrictions on transmissions of control plane data with carrier aggregation

ABSTRACT

The disclosure describes apparatus and methods for communicating control plane data with a mobile device in a Long Term Evolution (LTE) network employing carrier aggregation. A network apparatus, such as an enhanced NodeB (eNodeB) or a mobility management entity (MME), can be configured to evaluate a measurement report (MR) received from a mobile device for one or more radio frequency (RF) conditions associated with a primary network cell and one or more RF conditions associated with a secondary network cell. Then, based on the evaluation, the network apparatus can determine to communicate the control plane data with the mobile device via the primary network cell, the secondary network cell, or both. The control plane data can correspond to non-access stratum (NAS) information, radio resource control (RRC) information, or a hybrid automatic repeat request (HARQ) retransmission of previously transmitted control plane data.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application claims priority to U.S. Provisional Application No.61/913,725, filed on Dec. 9, 2013, and entitled “RESTRICTIONS ONTRANSMISSIONS OF CONTROL PLANE DATA WITH CARRIER AGGREGATION,” which isincorporated by reference herein in its entirety for all purposes.

FIELD

The described embodiments generally relate to wireless communications,and more particularly, to procedures for effectively communicatingcontrol-plane data between a network entity and a mobile device withindifferent carrier aggregation scenarios.

BACKGROUND

Fourth generation (4G) cellular networks employing newer radio accesstechnology systems that implement the 3^(rd) Generation PartnershipProject (3GPP) Long Term Evolution (LTE) and LTE Advanced (LTE-A)standards are rapidly being developed and deployed within the UnitedStates and abroad. LTE-A brings with it the aggregation of multiplecomponent carriers (CCs) to enable this wireless communications standardto meet the bandwidth requirements of multi-carrier systems thatcumulatively achieve data rates not possible by predecessor LTEversions.

Within both LTE and LTE-A telecommunication networks, the mobilitymanagement entity (MME) and the enhanced NodeB (eNodeB) base station areindependently responsible for implementing various control-planesignaling procedures. For example, the MME is responsible forestablishing and releasing radio bearer connections for user equipment(UE), affecting UE transitions from idle mode to connected mode (andvice versa) by generating corresponding paging messages, implementingvarious communication security features, etc. This functionality isreferred to as the Non-Access Stratum (NAS) within the LTE protocolarchitecture, which represents operations and communications between theevolved packet core (EPC) and the UE; the Access Stratum (AS) representsoperations and communications between the eNodeB and the UE within theLTE protocol architecture.

The eNodeB is responsible for various radio resource control (RRC)control-plane activities, including system information broadcasting,transmitting paging messages emanating from MMEs, RRC parameterconfiguration for UEs, network cell selection and reselectionprocedures, measurement and reporting configuration for UEs, etc. Invarious implementations, RRC control plane signaling may be performed inconjunction with one or more of the following LTE protocol entities orlayers: the packet data convergence protocol (PDCP), the radio linkcontrol (RLC) layer, the medium access control (MAC) layer, and thephysical (PHY) layer. Further, both control-plane data and user-planedata can be multiplexed within the MAC layer and communicated to anintended recipient via the PHY layer, in the downlink (DL) or in theuplink (UL), during the same transmission time interval (TTI).

Regardless of which network device, e.g., an MME or an eNodeB in the DL,or a UE in the UL, is communicating LTE control-plane data, it isgenerally understood that control-plane data consists of time-sensitiveinformation that must be communicated between or amongst various networkdevices in an efficient and predictable manner. Unfortunately, in modernLTE-A networks, which employ carrier aggregation to increase cumulativecommunications bandwidth and improve communications throughput,control-plane signaling (e.g., NAS or RRC communications) is not alwaysdesignated to the most appropriate DL or UL communication resource, toensure timely reception of sensitive control-plane data by one or moreintended recipients. In fact, the present 3GPP LTE-A standard (i.e.,relating to Releases 10-12) is silent with respect to identifying whichnetwork entity (e.g., a primary carrier cell or a secondary carriercell) is designated to communicate control-plane data corresponding toone or more component carrier network cells during various DLcommunications.

As such, there exists a need for solutions that restrict control-planedata communications to pre-designated network entities or todynamically-designated network entities as changing network conditionsmay require, particularly in view of various unanticipated radio linkfailure (RLF) scenarios. In this regard, it would be beneficial toimprove the likelihood of communicating control-plane data in a timelymanner within LTE-A networks employing carrier aggregation.

SUMMARY

This disclosure describes apparatus and procedures for communicatingcontrol plane data between a network apparatus and a mobile devicewithin a Long Term Evolution (LTE) network employing carrieraggregation. In various embodiments, a network apparatus, e.g., anenhanced NodeB (eNodeB) base station or a mobility management entity(MME), can be configured to evaluate one or more network conditionsassociated with a primary network cell and one or more networkconditions associated with a secondary network cell, determine when tocommunicate control plane data, e.g., corresponding to non-accessstratum (NAS) information or radio resource control (RRC) information,with the mobile device via the primary network cell or the secondarynetwork cell based at least in part on the evaluations of the networkconditions. Thereafter, the network apparatus can be configured to sendthe control plane data to the mobile device via the primary network cellor the secondary network cell, or both.

In accordance with some aspects, the primary network cell may be aprimary carrier cell of the mobile device and the secondary network cellmay be a secondary carrier cell of the mobile device, where both theprimary carrier cell (PCC) and secondary carrier cell (SCC) supportcarrier aggregation for the mobile device within the LTE network.

In various implementations, the primary network cell and the secondarynetwork cell can be configured as inter-band non-contiguous componentcarriers that respectively utilize different frequency resources withindifferent radio frequency (RF) bands for communicating with the mobiledevice.

In other aspects, the network apparatus can be configured to receive ameasurement report (MR) from the mobile device, where the MR includesinformation corresponding to the one or more network conditionsassociated with the primary network cell, as well as informationcorresponding to the one or more network conditions associated with thesecondary network cell.

In some scenarios, the MR may comprise one or more of a channel qualityindicator (CQI), a pre-coding matrix indicator (PMI), and a rankindicator (RI) for the primary network cell, and one or more of a CQI, aPMI, and a RI for the secondary network cell. Further, the one or morenetwork conditions associated with the primary network cell can bemeasured RF conditions of the primary network cell that comprise atleast one of a reference signal received power (RSRP), a received signalstrength indication (RSSI), and a signal to interference plus noiseratio (SINR). Similarly, the one or more network conditions associatedwith the secondary network cell can be measured RF conditions of thesecondary network cell that comprise at least one of a RSRP, a RSSI, anda SINR.

In some aspects, the network apparatus can be configured to evaluate atleast one of a circuit-switched fallback (CSF) condition for the mobiledevice and block error rate (BLER) information for instantaneousdownlink hybrid automatic repeat request (HARQ) at the network apparatusor for instantaneous uplink HARQ at the mobile device, and thendetermine to send the control plane data to the mobile device via theprimary network cell or the secondary network cell based at least inpart on evaluating at least one of the CSF condition for the mobiledevice and/or the corresponding BLER information.

In other aspects, the network apparatus can be configured to determineto send the control plane data to the mobile device via the primarynetwork cell when the one or more network conditions associated with theprimary network cell are better than the one or more network conditionsassociated with the secondary network cell, determine to send thecontrol plane data to the mobile device via the secondary network cellwhen the one or more network conditions associated with the secondarynetwork cell are better than the one or more network conditionsassociated with the primary network cell, or alternatively, determine tosend the control plane data to the mobile device via the primary networkcell by default (e.g., when the secondary network cell is assumed to bea less desirable option for communicating control plane data with themobile device by the network).

In one embodiment, the control plane data can be transmitted to themobile device via the primary network cell or the secondary network cellduring a network selected time interval; alternatively, the controlplane may not be transmitted to the mobile device until a MR is receivedfrom the mobile device.

In various embodiments, a network apparatus can comprise one or moreprocessors and a storage device storing executable instructions that,when executed by the one or more processors, cause the network apparatusto receive a MR from a user equipment (UE) communicating within an LTEnetwork, evaluate the MR to determine to communicate control plane datawith the UE using a PCC or a SCC, wherein the PCC and the SCC supportcarrier aggregation for the UE within the LTE network, and send thecontrol plane data to the UE via the PCC or the SCC.

In some aspects, execution of the executable instructions can furthercause the network apparatus to determine to communicate the controlplane data with the UE via the PCC and the SCC when the MR indicatesthat RF conditions are poor for the UE within the LTE network, and sendduplicate copies of the control plane data to the UE via the PCC and theSCC. In this regard, the duplicate copies of the control plane data canbe HARQ retransmissions of control plane data that was previously sentto the UE via the PCC or the SCC.

In other aspects, execution of the executable instructions may furthercause the network apparatus to determine to communicate the controlplane data with the UE via the PCC when the MR indicates that RFconditions for the PCC are better than RF conditions for the SCC, oralternatively, determine to communicate the control plane data with theUE via the SCC when the MR indicates that RF conditions for the SCC arebetter than RF conditions for the PCC. In either scenario, the controlplane data sent to the UE via the PCC or the SCC may be a HARQretransmission of control plane data that was previously sent to the UEvia the PCC or the SCC.

In some embodiments, a non-transitory computer readable medium can storeexecutable instructions that, when executed by one or more processors ofa network apparatus, cause the network apparatus to receive a MR from aUE communicating within an LTE network, evaluate the MR to determine tocommunicate control plane data with the UE using a PCC and a SCC whenthe MR indicates that RF conditions are poor for the UE within the LTEnetwork, where the PCC and the SCC support carrier aggregation for theUE, and then send duplicate copies of the control plane data to the UEvia the PCC and the SCC.

In various implementations, the duplicate copies of the control planedata can be HARQ retransmissions of control plane data that waspreviously sent to the UE via the PCC or the SCC.

This Summary is provided merely for purposes of summarizing some exampleembodiments so as to provide a basic understanding of some aspects ofthe subject matter described herein. Accordingly, it will be appreciatedthat the above-described features are merely examples and should not beconstrued to narrow the scope or spirit of the subject matter describedherein in any way. Other features, aspects, and advantages of thesubject matter described herein will become apparent from the followingDetailed Description, Figures, and Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The described embodiments and the advantages thereof may best beunderstood with reference to the following description taken inconjunction with the accompanying drawings. These drawings are notnecessarily drawn to scale, and they are in no way intended to limit orexclude foreseeable modifications thereto in form and detail that may bemade by one having ordinary skill in the art at the time of thisdisclosure.

FIG. 1 shows a wireless communication network including Long TermEvolution (LTE) and LTE Advanced (LTE-A) network cells supportingmultiple user equipment devices (UEs), which can be configured tocommunicate control-plane data in the downlink (DL) or in the uplink(UL), in accordance with various embodiments of the disclosure.

FIG. 2 shows a wireless communication network diagram depicting an LTE-Acompliant UE that is in communications with a primary carrier cell (PCC)and two secondary carrier cells (SCCs) in a carrier aggregationscenario, in accordance with various implementations of the disclosure.

FIGS. 3A-C show three distinct carrier aggregation representations thatdepict two intra-band component carrier (CC) frequency resource diagramsand one inter-band CC frequency resource diagram, in accordance withvarious embodiments of the disclosure.

FIG. 4 shows a block diagram of the LTE protocol architecture thatdelineates control-plane communications from user-plane communications,in accordance with some implementations of the disclosure.

FIG. 5 shows a network apparatus (e.g., an eNodeB or an MME) including anetwork resource controller having a control-plane signaling componentand a DL/UL HARQ scheduler component, in accordance with variousembodiments.

FIG. 6 shows a block diagram of a wireless communication deviceincluding a device resource manager having a control-plane signalingcomponent, a measurement and reporting component, and a HARQ signalingcomponent, in accordance with some implementations of the disclosure.

FIG. 7A shows a block diagram depicting a carrier aggregation scenariowhere a PCC is designated as a default network resource for conductingvarious control-plane data communications with a UE, in accordance withsome embodiments.

FIG. 7B shows a block diagram depicting a carrier aggregation scenariowhere control-plane data communications with a UE are dynamicallyallocated to either a PCC or to a preferred SCC based on various radiofrequency condition evaluations, in accordance with variousimplementations of the disclosure.

FIG. 8 shows a flowchart depicting a procedure for dynamicallydesignating a PCC or a SCC for conducting control-plane datacommunications, in accordance with some embodiments of the disclosure.

FIG. 9 shows a block diagram depicting DL HARQ scheduling withsemi-persistent scheduling (SPS) procedures for LTE communications, inaccordance with some implementations.

FIG. 10 shows a block diagram depicting UL HARQ scheduling proceduresfor LTE communications, in accordance with other embodiments of thedisclosure.

FIG. 11 shows a block diagram depicting a selective HARQ retransmissionof control-plane data between multiple network entities (e.g., a PCC anda SCC) and a UE in a carrier aggregation scenario, in accordance withvarious implementations.

FIG. 12 shows a flowchart depicting a procedure for performing selectiveHARQ retransmissions of control-plane data, in accordance with someembodiments of the disclosure.

FIG. 13 shows a block diagram depicting a dynamic HARQ retransmission ofcontrol-plane data between multiple network entities (e.g., a PCC and aSCC) and a UE, in accordance with various embodiments.

FIG. 14 shows a flowchart depicting a procedure for performing dynamicHARQ retransmissions of control-plane data, in accordance with someimplementations of the disclosure.

DETAILED DESCRIPTION

Representative examples for designating one or more network entities totransmit long term evolution (LTE) control-plane data in the downlink(DL) and/or in the uplink (UL) are described within this section.Further, various examples for performing selective and dynamic LTEhybrid automatic repeat request (HARQ) retransmissions of control-planedata, are also described herein. These examples are provided to addcontext to, and to aid in the understanding of, the subject matter ofthis disclosure. It should be apparent that the present disclosure maybe practiced with or without some of the specific details describedherein. Further, various modifications and/or alterations can be made tothe subject matter described herein, and illustrated in thecorresponding figures, to achieve similar advantages and results,without departing from the spirit and scope of the disclosure.

References are made in this section to the accompanying drawings, whichform a part of the disclosure and in which are shown, by way ofillustration, various implementations corresponding to the describedembodiments herein. Although the embodiments of this disclosure aredescribed in sufficient detail to enable one having ordinary skill inthe art to practice the described implementations, it should beunderstood that these examples are not to be construed as beingoverly-limiting or all-inclusive.

In accordance with various embodiments described herein, the terms“wireless communication device,” “wireless device,” “mobile device,”“mobile station,” and “user equipment” (UE) may be used interchangeablyherein to describe one or more common consumer electronic devices thatmay be capable of performing procedures associated with variousembodiments of the disclosure. In accordance with variousimplementations, any one of these consumer electronic devices may relateto: a cellular phone or a smart phone, a tablet computer, a laptopcomputer, a notebook computer, a personal computer, a netbook computer,a media player device, an electronic book device, a MiFi® device, awearable computing device, as well as any other type of electroniccomputing device having wireless communication capability that caninclude communication via one or more wireless communication protocolssuch as used for communication on: a wireless wide area network (WWAN),a wireless metro area network (WMAN) a wireless local area network(WLAN), a wireless personal area network (WPAN), a near fieldcommunication (NFC), a cellular wireless network, a fourth generation(4G) LTE, LTE Advanced (LTE-A), and/or 5G or other present or futuredeveloped advanced cellular wireless networks.

The wireless communication device, in some embodiments, can also operateas part of a wireless communication system, which can include a set ofclient devices, which can also be referred to as stations, clientwireless devices, or client wireless communication devices,interconnected to an access point (AP), e.g., as part of a WLAN, and/orto each other, e.g., as part of a WPAN and/or an “ad hoc” wirelessnetwork. In some embodiments, the client device can be any wirelesscommunication device that is capable of communicating via a WLANtechnology, e.g., in accordance with a wireless local area networkcommunication protocol. In some embodiments, the WLAN technology caninclude a Wi-Fi (or more generically a WLAN) wireless communicationsubsystem or radio, the Wi-Fi radio can implement an Institute ofElectrical and Electronics Engineers (IEEE) 802.11 technology, such asone or more of: IEEE 802.11a; IEEE 802.11b; IEEE 802.11g; IEEE802.11-2007; IEEE 802.11n; IEEE 802.11-2012; IEEE 802.11 ac; or otherpresent or future developed IEEE 802.11 technologies.

Additionally, it should be understood that the UEs described herein maybe configured as multi-mode wireless communication devices that are alsocapable of communicating via different third generation (3G) and/orsecond generation (2G) RATs. In these scenarios, a multi-mode UE can beconfigured to prefer attachment to LTE networks offering faster datarate throughput, as compared to other 3G legacy networks offering lowerdata rate throughputs. For instance, in some implementations, amulti-mode UE may be configured to fall back to a 3G legacy network,e.g., an Evolved High Speed Packet Access (HSPA+) network or a CodeDivision Multiple Access (CDMA) 2000 Evolution-Data Only (EV-DO)network, when LTE and LTE-A networks are otherwise unavailable.

FIG. 1 depicts a wireless communication system 100 that is compliantwith the 3GPP Evolved Universal Terrestrial Radio Access (E-UTRA) airinterface, and includes, but is not limited to including, one LTEnetwork cell 102 and two LTE-A network cells 104 a-b, respectivelyhaving enhanced NodeB (eNodeB) base stations (e.g., depicted as radiotowers) that can communicate between and amongst each other via theLTE-X2 interface. Further, the E-UTRA compliant communication system 100can include any number of mobility management entities (MMEs) 108 a-c,serving gateways (S-GWs) 108 a-c, PDN gateways (P-GWs) 110, etc., which,as part of the evolved packet core (EPC), can communicate with any ofthe LTE and LTE-A cell, 102 and 104 a-b, eNodeBs via the LTE-S1interface. Additionally, the E-UTRA communication system 100 can includeany number of UEs 106 that may be provided wireless communicationsservice by one or more of the eNodeBs of the LTE and LTE-A cells, 102and 104 a-b, at any particular time.

By way of example, a UE 106 may be located within one or more LTE-Acell(s) 104 a-b and in an LTE radio resource control (RRC) connectedmode when it initiates a voice over LTE (VoLTE) application to establisha voice call. The UE 106 running the VoLTE application can place a VoLTEvoice call to an intended recipient by communicating voice data to aserving eNodeB, which forwards the call through the EPC, 108 a-c and110, and thereby connects to the Internet 112 to transfer the VoLTEcommunications through an IP Multimedia Subsystem (IMS) network betweenthe caller UE 106 and a receiving device of the intended recipient,which may be a part of a remote network. Alternatively, the UE 106 caninitiate any number of different UE-resident applications that may berespectively associated with a particular data type, e.g., streamingaudio data, streaming audio-video data, website data, text data, etc.,to attempt to transfer IP-based application data via its serving LTE-Anetwork cell(s) 104 a-b over the Internet 112.

In various embodiments, any of the MMEs 108 a-c and/or any of the eNodeBbase stations of the LTE-A cells 104 a-b, which are capable ofsupporting carrier aggregation, can be configured to communicatecontrol-plane data to any of the UEs 106 in the DL. Alternatively, anyof the UEs 106 may be capable of communicating control-plane data viaany of the LTE-A cells 104 a-b in the UL. In this regard, it should beunderstood that the MMEs 108 a-b can perform Non-Access Stratum (NAS)control-plane signaling between the EPC and the UE 106 via the eNodeBover the radio access network (RAN) portion of the network. In somescenarios, NAS signaling can include, but is not limited to including,procedures for establishing and releasing radio bearer connections foruser equipment (UE), affecting UE transitions from idle mode toconnected mode (and vice versa) by generating corresponding pagingmessages, implementing various communication security features, etc.

Further, the eNodeB base stations of the LTE-A cells 104 a-b can beconfigured to perform various radio resource control (RRC) control-planesignaling procedures, including, but not limited to including, systeminformation broadcasting, transmitting paging messages emanating fromMMEs, RRC parameter configuration for UEs, network cell selection andreselection procedures, measurement and reporting configuration for UEs,etc. In various implementations, RRC control plane signaling may beperformed in conjunction with one or more of the following LTE protocolentities or layers: the packet data convergence protocol (PDCP), theradio link control (RLC) layer, the medium access control (MAC) layer,and the physical (PHY) layer. It should be understood that control-planedata and user-plane data can be multiplexed within the MAC layer andcommunicated to an intended recipient via the PHY layer, in the downlink(DL) or in the uplink (UL), e.g., during the same transmission timeinterval (TTI).

FIG. 2 shows a wireless communication network diagram 200 depicting anLTE-A compliant UE 206 that is in communications with a primary carriercell (PCC) 210 and two secondary carrier cells (SCCs), 212 and 214, in acarrier aggregation scenario. By way of example, and with reference to3GPP LTE-A Releases 10, 11, and 12, the LTE-A compliant UE 206 cancommunicate control-plane data with the eNodeB base station 202 (e.g.,in the DL or the UL) that can have multiple antennas for providing radiocoverage via three distinct radio frequency resources, F1, F2, and F3,which are individual component carriers (CCs) for communications thatcan be provided to UE 206 in aggregate, to increase communicationsbandwidth and throughput. From the perspective of the LTE-A compliant UE206, the CC radio frequency resource F1 can be associated with the PCC210, the CC radio frequency resource F2 can be associated with the SCC212, and the CC radio frequency resource F3 can be associated with theSCC 214. Alternative carrier aggregation representations for thisfrequency resource scenario will be described further herein for FIGS.3A-C.

The communication network diagram 200 also depicts two LTE compliantUEs, 204 and 208, with reference to 3GPP LTE Releases 8 and 9, which arenot capable of communicating using carrier aggregation. By way ofexample, the LTE compliant UE 204 can communicate control-plane datawith the eNodeB base station 202 (in the DL or the UL) via a singlefrequency resource F1, and the LTE compliant UE 208 may be configured tocommunicate control-plane data with the eNodeB base station 202 (in theDL or the UL) via a single frequency resource F3. In the single carrierscenario, LTE compliant UEs, 204 and 208, employ individualstandard-designated system bandwidths that limit achievable data ratethroughput to roughly 300 Mbits/sec. in the DL, and roughly 75Mbits/sec. in the UL (real world implementations may vary).

FIGS. 3A-C show three distinct carrier aggregation representationsdepicting two intra-band CC frequency resource diagrams, 300 and 310,and one inter-band CC frequency resource diagram 320, in accordance withvarious embodiments. As is generally understood, in 3GPP LTE and LTE-A,an individual CC is limited to communicating at various designatedsystem bandwidths 308 ranging from 1.4 MHz up to 20 MHz. As such, thecumulative DL data rate throughput achievable in carrier aggregationscenarios can increase the single carrier data-rate throughput ofroughly 300 Mbits/sec. by some multiplier value, relating to the numberof CCs employed (up to 5 CCs in LTE-A).

FIG. 3A shows a carrier aggregation representation depicting anintra-band contiguous CC frequency resource diagram 300, where eachaggregated CC, 302, 304, and 306, is associated with its own distinctfrequency resource, F1, F2, or F3, within the same service providerdesignated DL frequency band, Band A. In the intra-band contiguous CCscenario, the three frequency resources, F1, F2, and F3, are sequentialCC frequencies in the frequency domain.

FIG. 3B shows a carrier aggregation representation depicting anintra-band non-contiguous CC frequency resource diagram 310, where eachaggregated CC, 312, 314, and 316, is associated with its own distinctfrequency resource, F1, F2, or F3, within a single DL frequency band,Band A. However, in the intra-band non-contiguous CC scenario 310, thethree frequency resources, F1, F2, and F3, can be CC frequencies thatare respectively separated by one or more intervening frequencies in thefrequency domain, within Band A.

FIG. 3C shows a more common carrier aggregation representation depictingan inter-band non-contiguous CC frequency resource diagram 320, whereeach aggregated CC, 322, 324, and 326, is associated with its owndistinct frequency resource, F1, F2, or F3, within multiple serviceprovider designated DL frequency bands, Band A and Band B. In theinter-band non-contiguous CC scenario, the frequency resources, F1 andF2, of Band A can be CC frequencies that are separated from thefrequency resource F3 of Band B in the frequency domain. For reference,3GPP LTE-A Release 10 discusses carrier aggregation for LTE, and LTE-AReleases 11 and 12 describe various carrier aggregation enhancementsincluding various inter-band CC band pairings. It should be understoodthat telecommunications service providers generally operate using bothsimilar and dissimilar licensed LTE frequency spectrum bands. Forexample, within the United States, Verizon's® LTE networks operate inthe 700 and 1700/2100 Mhz frequency spectra using Bands 13 and 4,whereas AT&T's® LTE networks operate in the 700, 1700/2100, and 2300 MHzfrequency spectra using Bands 17, 4, and 30.

For telecommunication networks employing LTE-A, interoperability withpredecessor LTE versions requires an LTE-A CCs to employ a systembandwidth equivalent to its earlier LTE version counterparts. As such,the peak single CC LTE-A system bandwidth is capped at 20 MHz forinter-LTE RAT compatibility. However, in various carrier aggregationscenarios, an aggregate set of LTE-A CCs may be able to achievecumulative bandwidths of up to 100 MHz (5 CCs×20 MHz, the maximum LTEstandard system bandwidth) using one or more allocated LTE spectrumbands. Generally, UEs operating within LTE 102 and/or LTE-A 104 a-bnetwork cells employ operating bandwidths that mirror a serving cell(s)system bandwidth; this implementation ensures that sufficient radioresources are allocated to support different UE data typecommunications, having varying quality of service (QOS) requirements.

FIG. 4 shows a block diagram of the LTE protocol architecture 400 thatdelineates the control-plane from the user-plane amongst UE 402, eNodeB404, and MME 406 entities, in accordance with various implementations ofthe disclosure. As previously discussed, NAS signaling 408 a-b and RRCsignaling 410 a-b are associated with pure control-plane datacommunications within the LTE Protocol Architecture stack 400, whereasPDCP layer communications 412 a-b, RLC layer communications 414 a-b, MAClayer communications 416 a-b, and PHY layer communications 418 a-b maycomprise both control-plane and user-plane communications, depending ona particular implementation.

As is generally understood, the PDCP layer 412 a-b may be responsiblefor header de/compression of Internet Protocol (IP) data, transfer ofboth control-plane and user-plane data, maintenance of PDCP sequencenumbers (SNs), in-sequence delivery of upper layer protocol data units(PDUs) for lower layer reestablishments, duplicate elimination of lowerlayer service data units (SDUs) for lower layer reestablishments ofradio bearers mapped on the RLC layer 414 a-b, de/ciphering ofcontrol-plane and user-plane data, integrity protection and verificationof control-plane data, etc. The RLC layer 414 a-b may be responsible fortransferring upper layer PDUs, error-correction signaling,concatenation, segmentation and reassembly of RLC SDUs, re-segmentationof RLC data PDUs, reordering of RLC data PDUs, duplicate detection, RLCSDU discarding, RLC reestablishment, error detection, etc.

The MAC layer 416 a-b may be responsible for mapping between logicalchannels and transport channels, multiplexing of MAC SDUs from variouslogical channels onto transport blocks (TBs) to be delivered to the PHYlayer 418 a-b on transport channels, demultiplexing of MAC SDUs fromvarious logical channels from TBs delivered from the PHY layer 418 a-bon transport channels, scheduling information reporting,error-correction through HARQ signaling, priority handling between andamongst UEs via dynamic scheduling, priority handling between logicalchannels of a UE, logical channel prioritization, etc. The PHY layer 418a-b may be responsible for transferring information from various MAClayer 416 a-b transport channels over the E-UTRA air interface,controlling adaptive modulation and coding (AMC), performing Tx powercontrol procedures, performing cell searching during synchronization andhandover procedures, communication channel measurements for the RRClayer 410 a-b, etc.

FIG. 5 shows a network apparatus 500 that may be representative of aneNodeB 404 or an MME 406, in accordance with various embodiments. In onescenario, the network apparatus 500 may be a MME 406 that includes anetwork resource controller 512 with a control-plane signaling component514 that is capable of performing various NAS functions (described infurther detail herein), and processing circuitry 502 including one ormore processors 504 and a memory component 506. In another scenario, thenetwork apparatus 500 may be an eNodeB 404 base station that includes anetwork resource controller 512 with a control-plane signaling component514 that is capable of performing various RRC functions (described infurther detail herein), a DL radio resources assignment component 516,an UL radio resource assignment component 518, and a DL/UL HARQscheduler 520, as well as, processing circuitry 502 including one ormore processor(s) 504 and a memory component 506, and an RF circuit 508that includes an LTE modem and one or more wireless communicationstransceivers.

When the network apparatus 500 is representative of an eNodeB 404 basestation, the network resource controller 512 may be configured toutilize its DL radio resource assignment component 516 to generateand/or issue various DL radio resource assignments (e.g., carrier DL RBgrants) to one or more UEs located within its corresponding networkcells (e.g., within LTE-A PCC cell 210 and/or SCC cells 212 and 214).Further, the network resource controller 512 may also be configured toutilize its UL radio resource assignment component 514 to generateand/or issue various UL radio resource assignments (e.g., carrier UL RBgrants) to one or more UEs located within its corresponding networkcells (e.g., within LTE-A PCC cell 210 and SCC cells 212 and 214). Thenetwork resource controller 512 of the network apparatus 500 may be ableto employ its DL/UL HARQ scheduler component 520 to determine which UEs106 should receive various control-plane data HARQ retransmissions, andon what RBs these HARQ retransmissions should be communicated during arespective TTI, in the DL or in the UL.

In various configurations, the processing circuitry 502 of the networkapparatus 500 may be configured to perform various control-planesignaling activities, including control-plane data transmissions andHARQ retransmissions, e.g., by executing instructions of itscontrol-plane signaling component 514 and its DL/UL HARQ scheduler 520,in accordance with one or more embodiments disclosed herein. In thisregard, the processing circuitry 502 can be configured to perform and/orcontrol performance of one or more functionalities of the networkapparatus 500 in accordance with various implementations, and thus canprovide functionality for performing control-plane signaling operationsin the DL or in the UL, along with other communication procedures of thenetwork apparatus 500, in accordance with various embodiments. Theprocessing circuitry 502 may further be configured to perform dataprocessing, application execution, and/or other control and managementfunctions according to one or more embodiments of the disclosure.

The network apparatus 500, or portions or components thereof, such asthe processing circuitry 502, can include one or more chipsets, whichcan respectively include any number of coupled microchips thereon. Theprocessing circuitry 502 and/or one or more other components of thenetwork apparatus 500 may also be configured to implement functionsassociated with various selective HARQ retransmissions of control-planedata and dynamic HARQ retransmissions of control-plane data usingmultiple chipsets. In some scenarios, the network apparatus 500 may beassociated with, or employed as, a MME 108 a-c or an eNodeB base stationof one or more LTE-A cells 104 a-b, to operate within the wirelesscommunication system 100 of FIG. 1, or alternatively within the wirelesscommunication network 200 of FIG. 2. In this implementation, the networkapparatus 500 may include one or more chipsets configured to enable thenetwork apparatus 500 to operate within an LTE network employing carrieraggregation, as a network entity, or as joint network entities, capableof providing LTE-A communications service to any number of UEs 106located within its corresponding wireless coverage area(s) (e.g.,coverage areas associated with a PCC 210 and one or more SCCs, 212 and214, of FIG. 2).

In some scenarios, the processing circuitry 502 of the network apparatus500 may include one or more processor(s) 504 and a memory component 506.The processing circuitry 502 may be in communication with, or otherwisecoupled to, a radio frequency (RF) circuit 508 having an LTE-A compliantmodem and one or more wireless communication transceivers 510. Invarious implementations, the RF circuit 508 including the LTE-Acompliant modem and transceiver(s) 510 may be configured to communicateusing different LTE RAT types.

In various implementations, the processor(s) 504 may be configuredand/or employed in a variety of different forms. For example, theprocessor(s) 504 may be associated with any number of microprocessors,co-processors, controllers, or various other computing or processingimplements, including integrated circuits such as, for example, anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), or any combination thereof. In various scenarios,multiple processors 504 can be coupled to and/or configured in operativecommunication with each other and these components may be collectivelyconfigured to perform one or more procedures of the network apparatus500 as described herein in the form of an eNodeB base station having RRCcontrol functionality and/or in the form of a MME having NAS signalingfunctionality.

In some scenarios, the processor(s) 504 of the processing circuitry 502can be configured to execute instructions that may be stored in thememory 506 or that can be otherwise accessible to the processor(s) 504within some other device memory type. As such, whether configured as, orin conjunction with, hardware or a combination of hardware and software,the processor(s) 504 of the processing circuitry 502 may be capable ofperforming operations according to various implementations describedherein, when configured accordingly.

In various embodiments, the memory 506 of the processing circuitry 502may include multiple memory devices that can be associated with anycommon volatile or non-volatile memory type. In some scenarios, thememory 506 may be associated with a non-transitory computer-readablestorage medium that can store various computer program instructions,which may be executed by the processor(s) 504 during normal programexecutions. In this regard, the memory 506 can be configured to storeinformation, data, applications, instructions, or the like, for enablingthe network apparatus 500 to carry out various control-plane datasignaling and HARQ retransmission functions, in accordance with one ormore embodiments of the disclosure. In some implementations, the memory506 may be actively in communication with and/or coupled to theprocessor(s) 504 of the processing circuitry 502, as well as one or moresystem buses for passing information between and amongst the differentdevice components of the network apparatus 500.

It should be appreciated that not all of the components, deviceelements, and hardware illustrated in and described with respect to thenetwork apparatus 500 of FIG. 5 may be essential to this disclosure, andthus, some of these items may be omitted, consolidated, or otherwisemodified within reason. Additionally, in some implementations, thesubject matter associated with the network apparatus 500 can beconfigured to include additional or substitute components, deviceelements, or hardware, beyond those that are shown within theillustrations of FIG. 5.

FIG. 6 shows a block diagram of a wireless communication device 600(e.g., an LTE-A compliant UE) including a device resource manager 612having a control-plane signaling component 614, a measurement andreporting component 616, and a HARQ signaling component 618, as well as,processing circuitry 602 having one or more processor(s) 604 and amemory 606, and an RF circuit 608 having an LTE modem 610 and one ormore transceiver(s). In various configurations, the wirelesscommunication device 600 can employ its control-plane signalingcomponent 614 of its device resource manager 612 to perform both NAS andRRC signaling operations while in communication with an MME and/or andeNodeB base station.

Further, the wireless communication device 600 may employ itsmeasurement and reporting component 616 of its device resource manager612 to measure various radio frequency (RF) conditions, e.g., areference signal received power (RSRP), a received signal strengthindication (RSSI), a signal to interference plus noise ratio (SINR),etc., associated with any number of serving cells (e.g., for any of thePCC 210 and SCC, 212 and 214, cells of FIG. 2), at any particular time,and then transmit these measured RF conditions within a correspondingmeasurement report (MR), e.g., as one or more of a channel qualityindicator (CQI), a pre-coding matrix indicator (PMI), a rank indicator(RI), etc., within one or more periodic or aperiodic (networktrigger-initiated) MR(s). Additionally, the wireless communicationdevice 600 may employ its HARQ signaling component 618 of its deviceresource manager 612 to perform various HARQ signaling functions (e.g.,ACK/NACK messaging, UL re/transmissions, etc.), in accordance withvarious embodiments that are described further herein.

The processing circuitry 602 can be configured to perform and/or controlperformance of one or more functionalities of the wireless communicationdevice 600 in accordance with various implementations, and thus, theprocessing circuitry 602 can provide functionality for performingvarious control-plane signaling activities, including control-plane datatransmissions (e.g., NAS or RRC signaling) and HARQ retransmissions ofcontrol-plane data, e.g., by executing instructions of its control-planesignaling component 614 and its HARQ signaling component 618, inaccordance with one or more embodiments. In this regard, the processingcircuitry 602 can be configured to perform and/or control performance ofone or more functionalities of the wireless communication device 600 inaccordance with various implementations, and thus can providefunctionality for performing control-plane communications in the DL orin the UL, along with other communication procedures, in accordance withvarious embodiments. The processing circuitry 602 may further beconfigured to perform data processing, application execution, and/orother device functions according to one or more embodiments of thedisclosure.

The wireless communication device 600, or portions or componentsthereof, such as the processing circuitry 602, can include one or morechipsets, which can respectively include any number of coupledmicrochips thereon. The processing circuitry 602 and/or one or moreother components of the wireless communication device 600 may also beconfigured to implement functions associated with various control-planesignaling procedures of the disclosure using multiple chipsets. In somescenarios, the wireless communication device 600 may be associated with,or employed as, an LTE-A compliant UE 106 having multiple transceivers.

In various scenarios, the processing circuitry 602 of the wirelesscommunication device 600 may include one or more processor(s) 604 and amemory component 606. The processing circuitry 602 may be incommunication with, or otherwise coupled to, its radio RF circuit 608having an LTE compliant modem and one or more wireless communicationtransceivers 610. In some implementations, the RF circuit 608 includingthe modem and the one or more transceivers 610 may be configured tocommunicate using different RAT types. For instance, in some embodimentsthe RF circuit 608 may be configured to communicate using various RATs,including one or more LTE-A RATs.

In some embodiments, the processor(s) 604 may be configured in a varietyof different forms. For example, the processor(s) 604 may be associatedwith any number of microprocessors, co-processors, controllers, orvarious other computing or processing implements, including integratedcircuits such as, for example, an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA), or anycombination thereof. In various scenarios, multiple processors 604 ofthe wireless communication device 600 can be coupled to and/orconfigured in operative communication with each other, and thesecomponents may be collectively configured to perform one or morecontrol-plane signaling and/or HARQ retransmission procedures asdescribed further herein.

In some implementations, the processor(s) 604 can be configured toexecute instructions that may be stored in the memory 606, or that canotherwise be accessible to the processor(s) 604 in some other devicememory. As such, whether configured as, or in conjunction with, hardwareor a combination of hardware and software, the processor(s) 604 of theprocessing circuitry 602 may be capable of performing operationsaccording to various implementations described herein, when configuredaccordingly.

In various embodiments, the memory 606 of the processing circuitry 602may include multiple memory devices that can be associated with anycommon volatile or non-volatile memory type. In some scenarios, thememory 606 may be associated with a non-transitory computer-readablestorage medium that can store various computer program instructionswhich may be executed by the processor(s) 604 during normal programexecutions. In this regard, the memory 606 can be configured to storeinformation, data, applications, instructions, or the like, for enablingthe wireless communication device 600 to carry out various functions inaccordance with one or more embodiments of the disclosure. In someimplementations, the memory 606 may be in communication with, and/orotherwise coupled to, the processor(s) 604 of the processing circuitry602, as well as one or more system buses for passing information betweenand amongst the different device components of the wirelesscommunication device 600.

It should be appreciated that not all of the components, deviceelements, and hardware illustrated in and described with respect to thewireless communication device 600 of FIG. 6 may be essential to thisdisclosure, and thus, some of these items may be omitted, consolidated,or otherwise modified within reason. Additionally, in someimplementations, the subject matter associated with the wirelesscommunication device 600 can be configured to include additional orsubstitute components, device elements, or hardware, beyond thosedepicted within the illustrations of FIG. 6.

FIG. 7A shows a block diagram depicting a carrier aggregation scenario700 where a PCC 702 can be designated as a default networkentity/resource for communicating control-plane data (e.g., for NAS andRCC signaling) with a UE 706, in accordance with some embodiments of thedisclosure. In various implementations, the UE 706 may be an LTE-Acompliant mobile device (e.g., representative of the wirelesscommunication device 600 of FIG. 6) that can communicate with one ormore eNodeB base station(s), via the LTE-Uu interface, that may providethe UE 706 with wireless communications service via a PCC 702 and a SCC704, by employing LTE-A carrier aggregation RATs.

In an embodiment, all Level 1 (L1) PHY layer control data transmissions710 may be designated for the PCC 702 by default, and the PCC 702 mayadditionally communicate other IP packet data with the UE 706 in the DLor in the UL via the LTE-Uu interface. However, the SCC 704 may onlycommunicate IP packet data 712, without L1 control data, with the UE 706in the DL or in the UL, via the LTE-Uu Interface. The SCC 704 cancoordinate its packet data transmissions (including control-plane datacommunications) with the PCC 702 via an inter-cell coordination link714, via the LTE-X2 interface, to maximize communications throughput.

However, in certain situations, when time-sensitive control-plane data(e.g., NAS and RRC signaling) is communicated within packet datatransmissions from the PCC 702 to the UE 706, and from the SCC 704 tothe UE 706, independently, negative outcomes may result. By way ofexample, when communications between the SCC 704 and the UE 706 aredeemed by the network to be volatile, such as when RF conditions arepoor and communications degrade to the point where a RLF could result onthe communication link 712 between the SCC 704 and the UE 706, it may bedisadvantageous for the network to designate any control-plane datacommunications for the SCC 704. In this scenario, it is assumed that thePCC 702 will typically have a stronger communication link 710 with theUE 706, as compared to a communication link 712 between the SCC 704 andthe UE 706.

Accordingly, it may be particularly beneficial for the network topre-designate all control-plane data communications for the PCC 702, asopposed to the SCC 704, such that these time-sensitive control-planecommunications are only scheduled to occur via a more reliablecommunications link 708 between the PCC 702 and the UE 706. In variousembodiments, this designation may be implemented by the network in aneffort to prevent time-sensitive control-plane data from being lost inpredicable scenarios where a communication link between the SCC 704 andthe UE 706 may fail. This will improve the likelihood of the UE 706timely receiving sensitive control-plane data from the network via themost reliable communication link 708 available, between PCC 702 and theUE 706.

FIG. 7B shows a block diagram, similar to that of FIG. 7a , depictinganother carrier aggregation scenario 720 where control-plane data (e.g.,NAS and RCC information) communications for a UE 706 can be dynamicallyallocated to either the PCC 702 or to a preferred SCC 704, based onvarious RF condition evaluations (e.g., RF conditions that can bereceived by the PCC 702 within one or more periodic or aperiodic MRs)performed by a network entity (e.g., at an MME and/or an eNodeB basestation), in accordance with some embodiments of the disclosure. Invarious scenarios, the UE 706 may be an LTE-A compliant communicationdevice (e.g., representative of the wireless communication device 600 ofFIG. 6) that can communicate with one or more eNodeB base station(s),via the LTE-Uu interface, that may provide the UE 706 with wirelesscommunications service via a PCC 702 and a SCC 704, by employing LTE-Acarrier aggregation RATs.

In some embodiments, various network conditions associated with both acommunications link between the PCC 702 and the UE 706, and acommunications link between the SCC 704 and the UE 706, may be evaluatedby a network entity associated with at least the PCC 702 (e.g., an MMEand/or an eNodeB base station) to determine which of the two carriercells, the PCC 702 or the SCC 704, should be designated forcontrol-plane data communications.

For example, in some implementations, the PCC 702 (or a network entityassociated therewith) may receive either periodic or aperiodic (networktrigger-initiated) MRs 722 that can include CQI, PMI, and/or RIinformation relating to both RF conditions for the communications linkbetween the PCC 702 and the UE 706, and RF conditions for thecommunications link between the SCC 704 and the UE 706. In otherembodiments, the PCC 702 (or a network entity associated therewith) mayalready be aware of the RF conditions for these respectivecommunications links based on historical RF condition information storedby the network, e.g., at a network entity, such as an MME or an eNodeBbase station.

In some embodiments, a network entity associated with the PCC 702 (e.g.,an eNodeB base station) may evaluate respective RF conditions 724(received in MRs or maintained within a network entity) associated withthe PCC 702 and the SCC 704. In various scenarios, this may beaccomplished by comparing one or more common RF metrics of the LTE-Acommunication standard, to determine whether to dynamically designatethe PCC 702 or a SCC 704 as the preferred carrier cell “option” forperforming all subsequent control-plane signaling operations andcommunications with the UE 706 after a particular time, or during anetwork-selected time interval.

In one implementation, a network entity associated with the PCC 702 canselect a first option 726 a, based on comparing various RF conditionsassociated with one or more RF condition evaluations 724, by instructingthe PCC 702 to handle all control-plane signaling operations via a radiolink 728 a between the PCC 702 and the UE 706. This may occur when theradio link 728 a between the PCC 702 and the UE 706 is determined to bebetter than a radio link 728 b between the SCC 704 and the UE 706.Alternatively, in another implementation, a network entity associatedwith the PCC 702 or the SCC 704 can select a second option 726 b, basedon comparing various RF conditions associated with one or more radiolink evaluations 724, by instructing the SCC 704 to handle allcontrol-plane signaling operations via a radio link 728 b between theSCC 704 and the UE 706. This may occur when the radio link 728 b betweenthe SCC 704 and the UE 706 is determined to be better than a radio link728 a between the PCC 702 and the UE 706. It should be understood thatin various configurations, these control-plane signaling allocations forthe PCC 702 or the SCC 704, may be dynamically assigned forpre-determined periods of time or for indefinite periods of time thatmay be changed in real-time with the advent of various network conditiontriggers (e.g., in response to one or more MR trigger events).

FIG. 8 shows a flowchart depicting a procedure 800 for dynamicallydesignating a PCC 702 or a SCC 704 for conducting control-plane datacommunications with a UE 706, in accordance with some embodiments of thedisclosure. In this regard, it should be understood that any or all ofthe procedures 800 depicted in FIG. 8 may be associated with a method,or methods, that can be implemented by the execution of computer programinstructions stored in a non-transitory computer-readable memory 506 ofthe network apparatus 500, and optionally, in conjunction with theexecution of computer program instructions stored in a non-transitorycomputer-readable memory 606 of a wireless communication device 600.

Initially, at operation block 802, a network apparatus 500 (e.g., an MMEand/or an eNodeB base station) associated with a PCC 702 and/or a SCC704, may receive one or more periodic or aperiodic (networkevent-triggered) MRs from a particular wireless communication device 600(e.g., the UE 706 of FIGS. 7a-b ). Then, at operation block 804, thenetwork apparatus 500 and/or the wireless communication device 600 (oranother network entity associated therewith) may compare various RFchannel metrics (e.g., RSRP, RSRQ, SINR, etc.) associated with both acommunication link between a PCC 702 and the UE 706, and a communicationlink between a SCC 704 and the UE 706, to determine which of the twocells provides the most reliable RF conditions for subsequentcontrol-plane data communications with the UE 706.

In certain scenarios, the network can utilize information from one ormore MRs, if and when they become available, e.g., when they aretransferred to the network apparatus 500 from the wireless commutationdevice 600 via the measurement and reporting component 616, to make itsdetermination of a preferred cell for handling control-plane signalingcommunications. Alternatively, circuit-switched fallback (CSF)conditions (at the network apparatus 500), block error rate (BLER)information for instantaneous UL HARQ (at the UE 600) or for DL HARQ (atthe network apparatus 500) may also be evaluated to determine which ofthe two cells provides the most reliable and predictable RF conditionsfor subsequent control-plane data communications with the UE 706. Atdecision block 806, a determination is made as to whether the PCC 702 orthe SCC 704 is the preferred carrier cell for subsequent control-planedata communications with the UE 706.

In a scenario where the PCC 702 is determined to be the preferredcarrier cell for control-plane data communications, at operation block810, the PCC 702 can be designated by the network (e.g., at an MMEand/or an eNodeB base station) for handling future control-plane datasignaling operations and communications (e.g., for NAS and RRCmessaging). Alternatively, in a scenario where the SCC 704 is determinedto be the preferred carrier cell for control-plane data communications,at operation block 818, the SCC 704 may be designated by the network(e.g., at an MME and/or an eNodeB base station) for handling futurecontrol-plane data signaling operations and communications (e.g., forNAS and RRC messaging).

FIG. 9 shows a block diagram depicting DL HARQ scheduling withsemi-persistent scheduling (SPS) procedures 900 for LTE communications,in accordance with some implementations. In general, LTE HARQ processescan attempt to retransmit failed TB communications that may includecontrol-plane data in the DL and/or in the UL. The DL HARQ schedulingprocedures 900 depict signaling interactions between the physicaldownlink shared channel (PDSCH) 902, the physical downlink controlchannel (PDCCH) 904, and the physical uplink control channel (PUCCH)906, during various DL HARQ processes.

As would be understood by those skilled in the art, the PDCCH 904 mayinclude downlink control information (DCI), e.g., emanating from aneNodeB, that informs a UE 600 of various DL resource allocations for thePDSCH 902, HARQ information relating to the PDSCH 902, various ULscheduling grants for the physical uplink shared channel (PUSCH) 1002,etc. The PUCCH 906 can carry DL HARQ acknowledgements (e.g., ACK/NACKs)that are transmitted by a UE 600 to a network apparatus 500 in responseto the UE 600 receiving, or not receiving, various DL data transmissionsvia the PDSCH 902.

In some situations, a DL allocation 908 may be transmitted from anetwork apparatus 500 having DL HARQ scheduler 520 (e.g., an eNodeBhaving RRC functionality) within the PDCCH 904 to a UE 600 to identify aparticular set of designated DL resource blocks (RBs) where the UE 600should attempt to decode the PDSCH 902 for DL information that mayinclude control-plane data. Upon acquiring, or attempting to acquire,the identified DL information that may include control-plane data fromthe PDSCH 902 corresponding to the DL allocation 908, an intendedrecipient UE 600 can send a positive DL HARQ acknowledgement (ACK)message 910 or a negative DL HARQ acknowledgement (NACK) message 914 tothe network apparatus 500 via the PUCCH 906.

The DL HARQ ACK/NACK acknowledgements can indicate to the networkapparatus 500 (e.g., an eNodeB having RRC functionality) whether or notthe DL information was received or acquired by the UE 600 and/or whetherDL information that was acquired by the UE 600 is free from errors,e.g., according to a cyclic redundancy check (CRC) result. In somescenarios, a DL CRC success result 926 can indicate that DL informationwas acquired by a UE 600 with or without error. Alternatively, a DL CRCfailure result 928 may indicate that scheduled, expected DL informationwas not acquired by a UE 600. As would be understood by those skilled inthe art, a UE 600 will typically issue a DL HARQ ACK message to anetwork apparatus 500 (e.g., an eNodeB) via the PUCCH 906 in response toreceiving a DL CRC success result 926. Likewise, a UE 600 will typicallyissue a DL HARQ NACK message to a network apparatus 500 (e.g., aneNodeB) in response to receiving a DL CRC failure result 928.

In accordance with the DL HARQ SPS example 900, an ongoing SPS DLresource allocation 912 may be sent by a network apparatus 500 employingthe DL HARQ scheduler 520 (e.g., an eNodeB having RRC functionality) toa UE 600 to instruct the UE 600 to attempt to decode the PDSCH 902 forknown, recurring DL information on a periodic basis (e.g., every 10TTIs), such that the UE 600 is not required to further decode the PDCCH904 until a change to the ongoing SPS allocation 912 is detected.Accordingly, at every designated SPS interval (e.g., every 10 ms.) a UE600 can attempt to decode the PDSCH 902 for prescheduled DL information.Depending on whether or not the DL information has been successfullyacquired by the UE 600 via the PDSCH 902 and/or whether or not the DLinformation was acquired without errors, the UE 600 can send a DL HARQACK message 910, 920, 922, and 924, or a DL HARQ NACK message 914 to thenetwork apparatus 500 (e.g., an eNodeB) via the PUCCH 906.

In various implementations, upon receiving a DL HARQ NACK 914 messagevia the PUCCH 906 that indicates a DL transmission failure or error(e.g., corresponding to a CRC failure result 928), a network apparatus500 employing the DL HARQ scheduler 520 (e.g., an eNodeB having RRCfunctionality) can attempt to retransmit the DL information and/or aportion of the DL information 916 that may include control-plane data tothe UE 600 at a later time, in accordance with a designatedretransmission interval/duration (e.g., 4 TTIs later=4 ms.). In variousscenarios, a total retransmission time or round trip time (RTT) for theUE 600 to receive the correct and/or complete DL information may bescheduled to occur within a particular number of TTIs to account foranticipated network communication and device processing delays (e.g., aDL RTT of 8 TTIs=8 ms.).

In some scenarios, a network apparatus 500 employing the DL HARQscheduler 520 can evaluate a DL HARQ NACK 914 received via the PUCCH 906to determine when to schedule a DL retransmission 916 based on variousnetwork considerations, including an application data type beingcommunicated in the DL. The UE 600 can thereafter be informed of the DLretransmission schedule 916 by receiving a supplemental DL allocation918 for the retransmission within the PDCCH 904, as designated by thenetwork apparatus 500 (e.g., an eNodeB having RRC functionality). Aswould be understood by those skilled in the art, this DL HARQretransmission can occur on top of ongoing SPS operations, such that theDL HARQ procedures 900 requiring the UE 600 to decode the PDCCH 904 forretransmit control information will supersede SPS PDCCH “do not decode”durations.

FIG. 10 shows a block diagram depicting UL HARQ scheduling procedures1000 for LTE communications, in accordance with other embodiments of thedisclosure. Although not depicted in FIG. 10, it should be understoodthat in some implementations UL HARQ processes 1000 can occur inconjunction with SPS and/or C-DRX power saving routines. The UL HARQscheduling procedures 1000 depict signaling interactions between thePUSCH 1002, the PDCCH 1004, and the physical hybrid-ARQ indicatorchannel (PHICH) 1006, during various UL HARQ processes. As would beunderstood by those skilled in the art, the PHICH 1006 is configured tocarry UL HARQ acknowledgements (e.g., ACK/NACKs) that can be transmittedby a network apparatus 500 (e.g., an eNodeB) in response to receiving,or not receiving, various expected UL data transmissions from a UE 600that it provides LTE communications services to.

In some embodiments, an UL grant 1008 may be transmitted from a networkapparatus 500 employing an UL HARQ scheduler 520 (e.g., an eNodeB havingRRC functionality) within the PDCCH 1004 to a UE 600 to identify aparticular set of designated UL RBs where the UE 600 should attempt totransmit UL information to the network apparatus 500 in accordance witha predefined TTI interval (e.g., every 4 TTIs=4 ms.). In thisconfiguration, there will be a TTI delay between a time when the UE 600receives the UL grant 1008 via the PDCCH 1004 and a time when the UL RBsallocated to UE 600 for the UL transmission become available. The TTIdelay is intended to give the UE 600 sufficient time to process the ULdata and determine how best to transmit a corresponding UL TB, e.g., inaccordance with various network-designated quality of service (QoS)requirements.

Upon receiving, or attempting to receive, an UL transmission that mayinclude control-plane data via the PUSCH 1002, corresponding to an ULgrant, 1008 or 1012, a recipient network apparatus 500 (e.g., an eNodeB)can transmit either a positive UL HARQ acknowledgement (ACK) message1010 or a negative UL HARQ acknowledgement (NACK) message 1014 to thesending UE 600 via the PHICH 1006, e.g., on the DL from the networkapparatus 500. The UL HARQ ACK/NACK acknowledgements, 1010 and 1014, canindicate to the UE 600 whether or not an UL TB was received or acquiredby the network apparatus 500 and/or whether information of the UL TBthat was acquired by the network apparatus 500 is free from errors,e.g., according to a corresponding cyclic redundancy check (CRC) result,1020 or 1022. In various embodiments, an UL CRC success result 1020 canindicate that the UL TB was received by the network apparatus 500without error. Alternatively, an UL CRC failure result 1022 may indicatethat the UL TB was erroneously received by the network apparatus 500.

As would be understood by those skilled in the art, a network apparatus500 (e.g., an eNodeB having RRC functionality) will typically issue anUL HARQ ACK message to a corresponding UE 600 via the PHICH 1006 inresponse to an UL CRC success result 1020. Similarly, a networkapparatus 500 (e.g., an eNodeB having RRC functionality) will typicallyissue an UL HARQ NACK message to a UE 600 via the PHICH 1006 in responseto an UL CRC failure result 1022.

In some implementations, upon receiving an UL HARQ NACK 1014 via thePHICH 1006 from a network apparatus 500 that indicates an ULtransmission failure or error (e.g., corresponding to an UL CRC failureresult 1022), a UE 600 can attempt to retransmit the UL TB and/or aportion of the UL TB information 1016 that may include control-planedata to the network apparatus 500 at a later time, in accordance with adesignated retransmission interval (e.g., within 4 TTIs=4 ms.). Invarious scenarios, a total retransmission time or round trip time (RTT)for the network apparatus 500 to receive the correct and/or complete ULTB from the UE 600 may be scheduled to occur within a designated numberof TTIs associated with an UL HARQ RTT to account for anticipatednetwork communication and device processing delays (e.g., an UL RTT of 8TTIs=8 ms.).

FIG. 11 shows a block diagram depicting a selective retransmission 1100of control-plane data (e.g., NAS or RRC signaling data), emanating froma network RLC layer, between multiple network entities (e.g., a PCC 1102and a SCC 1104) and a UE 1106 in a carrier aggregation scenario. Itshould be understood that, in various embodiments, a retransmission 1100may occur in either the DL, between the PCC 1102, the SCC 1104, and theUE 1106, or in the UL between the UE 1106 and the PCC 1102 or the SCC1104. In accordance with some scenarios, the PCC 1102 may transmit TxData A 1108 to the UE 1106 via a first communication link, and the TxData A can include a first transmission of control-plane data (e.g., NASor RRC information) to the UE in the DL from the RLC layer of thenetwork.

In one scenario, the RLC layer associated with the UE 1106 may determinethat the Tx Data A, with the initial control-plane data, was received inerror. In response to this determination, the RLC layer of the UE 1106can transmit a HARQ NACK message to the PCC's 1102 corresponding HARQentity, which can then forward the NACK message to the RLC layer ofnetwork. In various implementations, the NACK message may include bitmapinformation that identifies the network resource allocation associatedwith Tx Data A.

The RLC layer of the network may use this NACK bitmap information tocoordinate with the PCC's 1102 HARQ entity and/or the SCC's 1104 HARQentity to schedule independent, duplicate retransmissions ofcontrol-plane Data A (ReTx Data A1 and ReTx Data A2) from both the PCC1102 and the SCC 1104 to the UE 1106, e.g., via separate communicationlinks 1114 a-b, to ensure that the first control-plane data transmissionis received by the UE 1106 in a timely and efficient manner via acorresponding RLC layer retransmission. Alternatively, in otherembodiments, the network can identify a situation where an expected ACKcorresponding to Tx Data A is not received from the UE 1106. In thisscenario the RLC layer of the network can similarly coordinate with thePCC 1102 and the SCC 1104 to schedule independent, duplicateretransmissions of the first control-plane data.

FIG. 12 shows a flowchart depicting a procedure 1200 for performingselective retransmissions of control-plane data (e.g., NAS and RRCcontrol information) emanating from the RLC layer of a network, inaccordance with some embodiments of the disclosure. In this regard, itshould be understood that any or all of the procedures 1200 depicted inFIG. 12 may be associated with a method, or methods, that can beimplemented by the execution of computer program instructions stored ina non-transitory computer-readable memory 506 of the network apparatus500, and optionally, in conjunction with the execution of computerprogram instructions stored in a non-transitory computer-readable memory606 of a wireless communication device 600.

Initially, at operation block 1202, a NACK for an initial control-planedata transmission may be received by a network apparatus 500 (e.g., anMME or an eNodeB base station) associated with a PCC 1102 or an SCC1104. Alternatively, the network apparatus 500 may be able to identify asituation where an expected ACK corresponding to the initialcontrol-plane data transmission is not received from the UE 1106. Atdecision block 1204, the network apparatus 500 may employ it RLC layerfunctions to determine whether a NACK response is received for theinitial control-plane data transmission or whether a missing ACKscenario has occurred for the initial control-plane data transmission.

In a scenario where the network apparatus 500 receives an ACK responsemessage for the initial control-plane data transmission 1210, theprocedure 1200 ends as no retransmission is required. However, in ascenario where the network apparatus 500 receives a NACK responsemessage for the initial control-plane data transmission, oralternatively, identifies a missing ACK scenario for the initialcontrol-plane data transmission, the process proceeds to operation block1206, where a duplicate HARQ retransmission for the initialcontrol-plane data transmission is scheduled for the PCC 1102 and forone or more SCCs 1104. Next at operation block 1208, the initialcontrol-plane data can be retransmitted to the UE 1106 from both the PCC1102 and the one or more SCCs 1104, to ensure that the initialcontrol-plane data is received by the UE 1106 in a timely manner.

FIG. 13 shows a block diagram depicting a dynamic HARQ retransmission1300 of control-plane data (e.g., NAS and RRC control information)between multiple network entities (e.g., a PCC 1302 and a SCC 1304) anda UE 1306 in a carrier aggregation scenario, in accordance with variousimplementations. It should be understood that HARQ retransmission 1300may occur in either the DL, between the HARQ entities of the PCC 1302and the SCC 1304 and the respective HARQ entities of the UE 1306 (e.g.,according to the DL HARQ retransmission 900 discussed above for FIG. 9),or in the UL between the first and second HARQ entities of the UE 1306and the respective HARQ entities of the PCC 1302 and the SCC 1304 (e.g.,according to the UL HARQ retransmission 1000 discussed above for FIG.10).

In accordance with various embodiments, the UE 1306 may be configured toemploy its measurement and reporting component 616 to transmit periodicor aperiodic (network event-triggered) MRs 1310 to a network entity 1312(e.g., an MME and/or an eNodeB base station) associated with the PCC1302 and/or the SCC 1304. Utilizing this information, the network entity1312 may be able to determine when RF signaling conditions are poor forthe UE 1306. When RF conditions experienced by the UE 1306 aredetermined to be poor, the network entity 1312 may coordinate with thePPC 1302 and the SCC 1304 HARQ entities to schedule (by default)duplicate retransmissions 1314 a-b for all control-plane datacommunications transmitted to the UE 1306 while the RF signalingconditions remain poor.

In this scenario, the PCC 1302 may transmit an initial Tx Data A(including control-plane data) to the UE 1306 over a first communicationlink 1308. The network may then employ the PCC's 1302 HARQ entity toretransmit a first copy of the ReTx Data A1 to the UE's 1306 first HARQentity via a first communication link 1316 a; the network may similarlyemploy the SCC's 1304 HARQ entity to retransmit a second copy of theReTx Data A2 to the UE's 1306 first HARQ entity via a secondcommunication link 1316 b. Upon receiving the first and second copies ofthe ReTx Data A1 and A2 by the UE's 1306 respective first and secondHARQ entities, the ReTx Data A1 and A2 can be passed through the MAClayer 1318 to the RLC layer 1320, which will utilize only one copy ofthe ReTx Data A1 or A2 for subsequent processing 1324. The remainder ofReTx Data A1 or A2 that is not utilized can be discarded 1322 at the RLClayer 1320 of the UE 1306.

FIG. 14 shows a flowchart depicting a procedure 1400 for performingdynamic HARQ retransmissions of control-plane data (e.g., NAS or RRCcontrol information), in accordance with some implementations of thedisclosure. In this regard, it should be understood that any or all ofthe procedures 1400 depicted in FIG. 14 may be associated with a method,or methods, that can be implemented by the execution of computer programinstructions stored in a non-transitory computer-readable memory 506 ofthe network apparatus 500, and optionally, in conjunction with theexecution of computer program instructions stored in a non-transitorycomputer-readable memory 606 of a wireless communication device 600.

Initially, at operation block 1402, a network apparatus 500 (e.g., anMME or an eNodeB base station) associated with a PCC 1302 or an SCC 1304may receive MR information corresponding the RF conditions experiencedby the UE 1306 for communications with the PCC 1302 and the SCC 1304.Next, at operation block 1404, the network apparatus 500 can evaluatethe MRs to determine whether network signaling conditions are poor,e.g., from the perspective of the UE 1306 for the PCC 1302 and/or theSCC 1304. At decision block 1406, a determination can be made as towhether network signaling conditions are poor for the UE 1306. In ascenario where network signaling conditions are determined not to bepoor, at operation block 1412, the network apparatus 500 can schedule asingle HARQ retransmission for control-plane data, e.g., when acorresponding NACK is received by the network. Then, at operation block1414 the single HARQ retransmission for the control-plane data may becommunicated to the UE 1306 from either the PCC 1302 or the SCC 1304.

Alternatively, in a scenario where network signaling conditions aredetermined to be poor, at operation block 1408, the network apparatus500 can schedule a duplicate transmission, i.e., the same RLC protocoldata unit (PDU), containing control-plane data for both the PCC 1302 andthe SCC 1304. Then, at operation block 1410, the PCC 1302 and the SCC1304 can retransmit respective, duplicate copies of the control planedata to the UE 1306, to ensure that the time-sensitive control-planedata is received by the UE 1306 in a timely manner.

The various aspects, embodiments, implementations or features of thedescribed embodiments can be used separately or in any combination.Further, some aspects of the described embodiments may be implemented bysoftware, hardware, or a combination of hardware and software. Thedescribed embodiments can also be embodied as computer program codestored on a non-transitory computer-readable medium. The computerreadable-medium may be associated with any data storage device that canstore data which can thereafter be read by a computer or a computersystem. Examples of the computer-readable medium include read-onlymemory, random-access memory, CD-ROMs, Solid-State Disks (SSD or Flash),HDDs, DVDs, magnetic tape, and optical data storage devices. Thecomputer-readable medium can also be distributed over network-coupledcomputer systems so that the computer program code may be executed in adistributed fashion.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatsome of the specific details are not required in order to practice thedescribed embodiments. Thus, the foregoing descriptions of specificembodiments are presented herein for purposes of illustration anddescription. These descriptions are not intended to be exhaustive,all-inclusive, or to limit the described embodiments to the preciseforms or details disclosed. It will be apparent to one of ordinary skillin the art that many modifications and variations are possible in viewof the above teachings, without departing from the spirit and the scopeof the disclosure.

What is claimed is:
 1. A method for designating control plane signalingoperations between a primary network cell and a secondary network cellof a Long Term Evolution (LTE) network, the method comprising: at anetwork apparatus in communication with a mobile device thatcommunicates with the LTE network via both the primary network cell andthe secondary network cell: evaluating one or more network conditionsassociated with downlink communication to the mobile device via theprimary network cell and one or more network conditions associated withdownlink communication to the mobile device via the secondary networkcell; determining whether to communicate control plane data to themobile device via the primary network cell, via the secondary networkcell, or via both the primary and secondary network cells based at leastin part on the evaluating; and sending the control plane data to themobile device via the primary network cell, via the secondary networkcell, or via both the primary and secondary network cells based at leastin part on the determining.
 2. The method of claim 1, wherein: thecontrol plane data corresponds to non-access stratum (NAS) informationor radio resource control (RRC) information; and the network apparatusis an enhanced NodeB (eNodeB) base station or a mobility managemententity (MME) of the LTE network.
 3. The method of claim 1, wherein: theprimary network cell is a primary carrier cell of the mobile device andthe secondary network cell is a secondary carrier cell of the mobiledevice; and the primary carrier cell and secondary carrier cell providecommunication using carrier aggregation for the mobile device within theLTE network.
 4. The method of claim 3, wherein the primary network celland the secondary network cell communicate with the mobile device usinginter-band non-contiguous component carriers that utilize differentfrequency resources within different radio frequency (RF) bands.
 5. Themethod of claim 1, further comprising: receiving at least onemeasurement report (MR) from the mobile device, wherein the at least oneMR includes information corresponding to the one or more networkconditions associated with downlink communication to the mobile devicevia the primary network cell and information corresponding to the one ormore network conditions associated with downlink communication to themobile device via the secondary network cell.
 6. The method of claim 5,wherein the at least one MR comprises one or more of: a channel qualityindicator (CQI), a pre-coding matrix indicator (PMI), or a rankindicator (RI) for the primary network cell, and one or more of: a CQI,a PMI, or a RI for the secondary network cell.
 7. The method of claim 1,wherein: the one or more network conditions associated with downlinkcommunication to the mobile device via the primary network cell aremeasured radio frequency (RF) conditions of the primary network cellthat comprise at least one of: a reference signal received power (RSRP),a received signal strength indication (RSSI), or a signal tointerference plus noise ratio (SINR); and the one or more networkconditions associated with the downlink communication to the mobiledevice via secondary network cell are measured RF conditions of thesecondary network cell that comprise at least one of: the RSRP, theRSSI, or the SINR.
 8. The method of claim 1, further comprising:evaluating at least one of: a circuit-switched fallback (CSF) conditionfor the mobile device, or block error rate (BLER) information forinstantaneous downlink hybrid automatic repeat request (HARQ) at thenetwork apparatus or for instantaneous uplink HARQ at the mobile device,wherein the determining whether to communicate control plane data to themobile device via the primary network cell, via the secondary networkcell, or via both the primary and second network cells is further basedat least in part on the evaluating the at least one of the CSF conditionfor the mobile device or the BLER information.
 9. The method of claim 1,wherein the network apparatus sends the control plane data to the mobiledevice: via the primary network cell when the one or more networkconditions associated with downlink communication to the mobile devicevia the primary network cell are better than the one or more networkconditions associated with downlink communication to the mobile devicevia the secondary network cell; via the secondary network cell when theone or more network conditions associated with downlink communication tothe mobile device via the secondary network cell are better than the oneor more network conditions associated with downlink communication to themobile device via the primary network cell; and via the primary networkcell by default.
 10. The method of claim 1, further comprising:continuing to send the control plane data to the mobile device via theprimary network cell, via the secondary network cell, or via both theprimary and secondary network cells during a network selected timeinterval or until a measurement report (MR) is received from the mobiledevice.
 11. A network apparatus, comprising: one or more processors; anda storage device storing executable instructions that, when executed bythe one or more processors, cause the network apparatus to: receive ameasurement report (MR) from a user equipment (UE) communicating withina Long Term Evolution (LTE) network; evaluate the MR received from theUE to determine whether to communicate control plane data in thedownlink direction to the UE via a primary carrier cell (PCC), via asecondary carrier cell (SCC), or via both the PCC and the SCC, the PCCand the SCC providing communication with carrier aggregation for the UEwithin the LTE network; and send the control plane data to the UE viathe PCC, via the SCC, or via both the PCC and the SCC based at least inpart on evaluation of the MR received from the UE.
 12. The networkapparatus of claim 11, wherein the network apparatus sends duplicatecopies of the control plane data to the UE via both the PCC and the SCCwhen the MR indicates that radio frequency (RF) conditions are poor fordownlink communication to the UE within the LTE network.
 13. The networkapparatus of claim 12, wherein the duplicate copies of the control planedata sent to the UE via both the PCC and the SCC are hybrid automaticrepeat request (HARM) retransmissions of control plane data previouslysent to the UE via the PCC or via the SCC.
 14. The network apparatus ofclaim 11, wherein the network apparatus communicates the control planedata to the UE: via the PCC when the MR indicates that radio frequency(RF) conditions for downlink communication to the UE via the PCC arebetter than RF conditions for downlink communication to the UE via theSCC; and via the SCC when the MR indicates that RF conditions fordownlink communication to the UE via the SCC are better than RFconditions for downlink communication to the UE via the PCC.
 15. Thenetwork apparatus of claim 14, wherein the control plane data sent tothe UE via the PCC or the SCC is a hybrid automatic repeat request(HARM) retransmission of control plane data previously sent to the UEvia the PCC or the SCC.
 16. The network apparatus of claim 11, whereinthe PCC and the SCC communicate with the UE using inter-bandnon-contiguous component carriers that utilize different frequencyresources within different radio frequency (RF) bands.
 17. The networkapparatus of claim 11, wherein the MR comprises one or more of: achannel quality indicator (CQI), a pre-coding matrix indicator (PMI), ora rank indicator (RI) for the PCC, and one or more of: a CQI, a PMI, ora RI for the SCC.
 18. A non-transitory computer readable medium storingexecutable instructions that, when executed by one or more processors ofa network apparatus, cause the network apparatus to: receive ameasurement report (MR) from a user equipment (UE) communicating withina Long Term Evolution (LTE) network; evaluate the MR received from theUE to determine whether to communicate control plane data in thedownlink direction to the UE via a primary carrier cell (PCC), via asecondary carrier cell (SCC), or via both the PCC and the SCC, the PCCand the SCC providing communication with carrier aggregation for the UEwithin the LTE network; and send duplicate copies of the control planedata to the UE via both the PCC and the SCC when the MR indicates thatradio frequency conditions (RF) are poor for the UE within the LTEnetwork.
 19. The non-transitory computer readable medium of claim 18,wherein the duplicate copies of the control plane data sent to the UEvia both the PCC and the SCC are hybrid automatic repeat request (HARQ)retransmissions of control plane data previously sent to the UE via thePCC or via the SCC.
 20. The non-transitory computer readable medium ofclaim 18, wherein the PCC and the SCC communicate with the UE usinginter-band non-contiguous component carriers that utilize differentfrequency resources within different radio frequency (RF) bands.